Certain glycoantigens, e.g., Tn, sTn, GM2, and Globo H, have been found to be overly expressed on cancer cells. These antigens, particularly their sugar epitopes, are targets in cancer diagnosis and immune therapy.
As sugar epitopes typically have low immunogenicity, they are routinely conjugated with keyhole limpet hemocyanin (KLH) or bovine serum albumin (BSA) as a protein carrier to elicit strong immune responses. However, this approach has at least two disadvantages. First, the conjugation efficiency between KLH/BSA and a sugar epitope is generally low. Second, the resultant conjugate would elicit immune responses not specific to the sugar epitope.
There is a need for a new approach to improve immunogenicity of a low-antigenic molecule.